SIP Trunking is a technology and service in telecommunications that enables the routing of voice and data calls over the internet or an IP network using the Session Initiation Protocol (SIP). It allows businesses to connect their Private Branch Exchange (PBX) phone systems to the public switched telephone network (PSTN) or other communication systems via the internet, eliminating the need for traditional phone lines. SIP Trunking offers cost savings, scalability, and flexibility for businesses, making it an attractive option for modern voice communication solutions.